AD 77-25-05

final rule
Data completeness: 70%

Airworthiness Directives; Enstrom Model F28C and 280C Helicopters

AD Number
77-25-05
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Enstrom Helicopter Corporation, The 280C Airworthiness Directives; Enstrom Model F28C and 280C Helicopters
aircraft Enstrom Helicopter Corporation, The F-28C Airworthiness Directives; Enstrom Model F28C and 280C Helicopters

Unsafe Condition

Improper idle mixture adjustment and internal injector leakage can cause RPM fluctuations and engine stoppage during flight, leading to loss of engine power.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect and adjust idle mixture per Enstrom Service Information Letter No. 0069 steps 4C-4G. Install Enstrom Kit 28-121015 within three calendar months or 100 hours time in service. Update RFM with specified limitations, procedures, and placards.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Prior to further flight and within the next three calendar months or 100 hours time in service, whichever occurs first.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Enstrom Helicopter Corporation models F28C and 280C helicopters certificated in all categories.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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